This invention pertains to apparatuses and methods in the field if immunology. More in particular, the invention pertains to genetic engineering, hybridomas and monoclonal antibodies. Furthermore, this invention relates to forensic methods used in analyzing sexual assault evidence.
Current analyses of sexual assault evidence involves testing for prostatic acid phosphatase (F. M. Poyntz and P. D. Martin, Forensic Sciences International, 24, 17, (1984)), prostatic antigen (G. F. Sensabaugh, J. Forensic Sci. 23, 106 (1978)), and microscopic evidence of spermatozoa. These tests are employed for the positive identification of human semen found in and around the sexual assault victim. The test for prostatic acid phosphatase has the drawback that endogenous vaginal acid phosphatase exists at such levels that the upper limit of the range in vaginal acid phosphatase concentrations overlaps with the lower limit of the range of seminal fluid acid phosphatase (R. E. Gaensslen, Sourcebook in Forensic Serology, Immunology and Biochemistry, U.S. Department of Justice, Washington, D.C. (U.S. Government Printing Office, 1983)). Furthermore, a number of materials having plant origin give high acid phosphatase values. Moreover, the acid phosphatase activity of seminal stains declines by 50 to 80 percent when stored at room temperature for several months. For these reasons the assay for acid phosphatase is considered by forensic specialists to be a presumptive rather than a diagnostic assay for semen.
The microscopic identification of spermatozoa in sexual assault cases is a method hampered by the age of the evidence and the adherence of spermatozoa to material comprising criminal evidence. These difficulties often result in the failure to identify spermatozoa.
Prostate specific antigen, p30, a 32 kilodalton protein of prostatic origin, has been identified with polyclonal antisera since 1978 (G. F. Sensabaugh, J. Forensic Sci. 23, 106 (1978); H. Graves, G. F. Sensabaugh and E. T. Black, New England J. Med. 312 (6) 338 (1985)). In current forensic practice this is semen specific marker offers some advantages over protatic acid phosphatase and is widely employed (F. M. Poyntz and P. D. Martin, Forensic Sciences International, 24, 17 (1984); G. F. Sensabaugh, J. Forensic Sci. 23, 106 (1978)). A monoclonal antibody to p30 is available, however its application to forensic casework has not been reported (A. E. Frankel, R. V. Rouse, M C. Wang and T. M. Chu, Cancer Research 42, 3714 (1982)).
The prostate is one of two male accessory organs which contribute secretions to the ejaculate volume. The prostate contributes 15 to 30 percent and the seminal vesicles contribute 50 to 80 percent of the ejaculate volume (T. Mann and C. Lutwak-Mann. Male Reproductive Function and Semen, (Springer-Verlag, Berlin, 1981), p. 183). Because of their relatively large contributions to the total ejaculate volume, secretions from these organs are candidates for forensic markers.
There is a very real problem in criminal prosecutions of sexual assaults dealing with obtaining positive evidence of the sexual assault. The best positive evidence is semen identification. The problem with semen identification is the relatively small quantities present at the scene of the crime. The normal semen volume averages 3.5 mls with the usual range of 1.5 to 5.0 mils (Clinical Diagnosis by Laboratory Methods, Davidsohn and Henry, 15th edition, p. 1301). Logic dictates that the most advantageous candidate for forensic markers would be antigens located in that portion of the ejaculate which is most voluminous, i.e., seminal vesicles or prostate secretions. This is to maximize the probability that evidence of sexual assault will be more positively identified.
The present invention solves the problems in the prior art and does so more advantageously than any attempt to date.